package cn.wolfcode.util;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RequestUtil {


        private static final String[] HEADERS = {
                "X-Forwarded-For",
                "Proxy-Client-IP",
                "WL-Proxy-Client-IP",
                "HTTP_X_FORWARDED_FOR",
                "HTTP_X_FORWARDED",
                "HTTP_X_CLUSTER_CLIENT_IP",
                "HTTP_CLIENT_IP",
                "HTTP_FORWARDED_FOR",
                "HTTP_FORWARDED",
                "HTTP_VIA",
                "REMOTE_ADDR",
                "X-Real-IP"
        };

        /**
         * 判断ip是否为空，空返回true
         * @param ip
         * @return
         */
        public static boolean isEmptyIp(final String ip){
            return (ip == null || ip.length() == 0 || ip.trim().equals("") || "unknown".equalsIgnoreCase(ip));
        }


        /**
         * 判断ip是否不为空，不为空返回true
         * @param ip
         * @return
         */
        public static boolean isNotEmptyIp(final String ip){
            return !isEmptyIp(ip);
        }

        /***
         * 获取客户端ip地址(可以穿透代理)
         * @param request HttpServletRequest
         * @return
         */
        public static String getIpAddress(HttpServletRequest request) {
            String ip = "";
            for (String header : HEADERS) {
                ip = request.getHeader(header);
                if(isNotEmptyIp(ip)) {
                    break;
                }
            }
            if(isEmptyIp(ip)){
                ip = request.getRemoteAddr();
            }
            if(isNotEmptyIp(ip) && ip.contains(",")){
                ip = ip.split(",")[0];
            }
            if("0:0:0:0:0:0:0:1".equals(ip)){
                ip = "127.0.0.1";
            }
            return ip;
        }


        /**
         * 获取本机的局域网ip地址，兼容Linux
         * @return String
         * @throws Exception
         */
        public String getLocalHostIP() throws Exception{
            Enumeration<NetworkInterface> allNetInterfaces = NetworkInterface.getNetworkInterfaces();
            String localHostAddress = "";
            while(allNetInterfaces.hasMoreElements()){
                NetworkInterface networkInterface = allNetInterfaces.nextElement();
                Enumeration<InetAddress> address = networkInterface.getInetAddresses();
                while(address.hasMoreElements()){
                    InetAddress inetAddress = address.nextElement();
                    if(inetAddress != null && inetAddress instanceof Inet4Address){
                        localHostAddress = inetAddress.getHostAddress();
                    }
                }
            }
            return localHostAddress;
        }

    }

